1. Field of the Invention
The present invention relates to an absorbent article capable of absorbing and retaining liquids discharged from the wearer ""s body such as typically menses, urine and others. More particularly, it relates to an absorbent article which hardly gives a wet feel to the skin of a wearer when a small amount of liquid such as sweat has adhered to its liquid-receiving face.
2. Description of the Related Art
Various absorbent articles such as sanitary napkins, incontinence pads, disposable diapers and others have heretofore been developed and known. These absorbent articles comprise a liquid-impermeable backsheet, a liquid-permeable topsheet, and an absorbent core therebetween.
Regarding the structure of the topsheet of the absorbent articles of those types, for example, there has been known an absorbent article in which a topsheet is formed from a plastic film having apertures. In this absorbent article, liquid given to the surface of the film passes through the apertures and is absorbed by the absorbent core that underlies the film. Since the film is non-absorbent by itself, it can prevent the liquid having been once absorbed by the absorbent core from returning to the surface of the film.
More specifically, when a large amount of liquid is given to the surface of the film of the absorbent article, it passes through the apertures to immediately come into contact with the absorbent core underlying it, so that the liquid on the surface of the film is drawn by the absorbent core owing to the hydrophilic capillary action of the absorbent core. Since the topsheet made of the film is poorly wettable with fluid, it rapidly passes the large amount of liquid through the apertures. Thus, almost all the liquid given thereto is immediately absorbed by the absorbent core.
However, when a small amount of liquid is left on the surface of the topsheet or when sweat of a wearer is adhered thereon, the absorbent core cannot exert its absorbing power on such a small amount of liquid. Therefore, the liquid is liable to remain on the film surface. The small amount of liquid thus remaining on the film surface may be brought into contact with the skin of a wearer or vaporized to stay around it, resulting in a wet or stuffy feel to the skin of a wearer to cause skin roughness. In addition, the topsheet made of the film often sticks to the skin of a wearer, thereby to increase the wet feel.
In Japanese Unexamined Patent Publication (Tokuhyo) No. 500759/1995, on the other hand, there is disclosed an absorbent article in which a fibrous sheet is joined in a screen pattern to the back of a plastic film having apertures. In this absorbent article, a large amount of liquid given to the topsheet smoothly passes through the film and is then distributed to the absorbent core through the fibrous layer. However, it is still difficult to absorb a small amount of liquid left on the surface of the topsheet, sweat adhered thereon and so on.
On the other hand, in the prior art, there have been known absorbent articles having leakage-preventing side walls on the liquid-receiving side thereof, which extend in the longitudinal direction of the article and are positioned on both sides lying opposite one another in the width direction of the article. The leakage-preventing side wall is formed from a nonwoven fabric or the like of hydrophobic synthetic fibers. The nonwoven fabric of hydrophobic synthetic fibers is resistant to liquid permeation therethrough, so that it exhibits the function of preventing leakage of liquid in the width direction as having the ability to return a large amount of liquid having been give thereto to the topsheet of the absorbent article. However, this nonwoven fabric cannot lead a small amount of liquid such as sweat having been adhered thereto to the topsheet, so that the liquid or its vapor will remain between the leakage-preventing side wall and the skin of a wearer, and will give a wet feel to the wearer""s skin.
The present invention has been worked out in view of the shortcoming in the prior art set forth above. It is therefore an object of the present invention to provide an absorbent article which is so designed that a small amount of liquid or its vapor does not remain on its liquid-receiving face in order not to give a wet feel to the skin of a wearer.
According to one aspect of the invention, there is provided an absorbent article comprising a topsheet, a backsheet and an absorbent core positioned between the topsheet and the backsheet, wherein
the topsheet includes: a resin layer having a plurality of apertures and forming a liquid-receiving face of the topsheet; and a fibrous layer underlying the resin layer, and
the fibrous layer contains hydrophobic fibers and hydrophilic fibers shorter than the hydrophobic fibers, at least a part of the hydrophilic fibers form aggregates that disperse in the fibrous layer, and at least a part of the aggregates are bonded to the surfaces of the hydrophobic fibers. In the topsheet, preferably, the fibrous layer is formed with a plurality of through-holes.
According to another aspect of the invention, there is provided an absorbent article comprising a topsheet, a backsheet and an absorbent core positioned between the topsheet and the backsheet, and having leakage-preventing side walls on a liquid-receiving side of the article, the leakage-preventing side walls extending in a longitudinal direction of the article and lying opposite one another in a width direction of the article, wherein
the leakage-preventing side wall includes: a resin layer having a plurality of apertures and forming a liquid-receiving face of the side wall; and a fibrous layer underlying the resin layer, and
the fibrous layer contains hydrophobic fibers and hydrophilic fibers shorter than the hydrophobic fibers, at least a part of the hydrophilic fibers form aggregates that disperse in the fibrous layer, and at least a part of the aggregates are bonded to the surfaces of the hydrophobic fibers.
In the fibrous layer, preferably, the fiber density of the hydrophilic fiber aggregates is higher than the fiber density of a portion of the fibrous layer not containing the aggregates therein.
The fibrous layer may contain from 70 to 98% by weight of hydrophobic fibers and from 2 to 30% by weight of hydrophilic fibers.
The hydrophobic fibers may have a length of from 38 to 64 mm, and the hydrophilic fibers may have a length of from 5 to 25 mm. Preferably, the length of the hydrophilic fibers is at most xc2xd of that of the hydrophobic fibers. If the fiber lengths are within the ranges, the hydrophilic fibers can be readily massed or crimped to form the aggregates and dispersed among the hydrophobic fibers by using a conventional carding unit.
In the absorbent article according to the invention, the liquid-receiving face of the topsheet or side wall is made of the resin layer having the plurality of apertures. Therefore, a large amount of liquid having been given thereto can immediately pass through the apertures therein to thereby prevent the occurrence of residual liquid on the liquid-receiving face. Since the hydrophilic fiber aggregates are dispersed in the fibrous layer underlying the resin layer, on the other hand, when a small amount of liquid, such as sweat of a wearer, or its vapor, is given to the topsheet or side wall, the liquid or vapor can be absorbed by the hydrophilic fiber aggregates so that the liquid-receiving face can be kept always dry.